the practice of using la as indirect object pronoun when referring to feminine nouns, instead of the standard le
“El laísmo consiste en emplear los pronombres de complemento directo (la, las) como forma de complemento indirecto referido a sustantivos femeninos, cuyas formas deben ser le, les: A María la rompieron la falda (correcto, le)” — Laísmo consists of using direct object pronouns (la, las) as the form of the indirect object referring to feminine nouns, whose forms should be le, les: A María la rompieron la falda "They tore María's skirt" (correct: le).
Etymology tree Spanish la Proto-Indo-European *-id- Proto-Indo-European *-yéti Proto-Indo-European *-idyéti Proto-Hellenic *-íďďō Ancient Greek -ῐ́ζω (-ĭ́zō) Proto-Indo-European *-mos Proto-Indo-European *-mós Ancient Greek -μός (-mós) Ancient Greek -ῐσμός (-ĭsmós)der. Latin -ismusbor. Spanish -ismo Spanish laísmo From la + -ismo.